lOO 



Garden and Forest. 



[April 25, 18 



nearly New Year's has the ruddy tinting given way to 

 brown. Even then the tree remains a prominent object, 

 and is, indeed, even for an Oak, one among a thousand. 

 For the past fourteen years this tree has never failed to 

 retain nearly all its leaves, although in that time there has 

 been every variety of summer and winter that even the 

 powers in charge of our capricious climate could invent. 



On examination of the Oaks near by, it has seemed to 

 me that they all have a tendency to retain their leaves, and 

 the measure of success in each case is due principally to 

 the exposure of the tree and its general vigor. Here I may 

 be wholly at sea, and only too glad to be informed cor- 

 rectly, if in error. 



What I have said of Oaks applies equally to the Beech. 

 Given shelter from the north-west winds and average vigor, 

 and many a leaf will cling to its parent stem, until the 

 swelling leaf buds of the new year shall crowd it from its 

 place. 



While yet the drifts of the late great snow storm still 

 lingered, it was a pleasant feature of the landscape to see 

 the sapling Beeches still bearing aloft their last year's 

 leaves, dimly glittering like wrinkled fragments of old 

 gold, and filling the air with a bell-like tinkle, soothing 

 and soft as the twitter of a bird. 



I offer it as a hint to the landscape gardener, to bring 

 about by selection, if it can be done, a fully established 

 habit of leaf retention ; not makimj evere^reen Oaks, but 

 winter-long, bright brown Oaks; for such now lessen, to a 

 marked degree, the dreariness of many a winter outlook. 

 Again, when leaf retaining Oaks are mingled with Ever- 

 greens, there is an added charm to the scene. Think for a 

 moment of such a cluster as this : A background of Cedar, 

 scattered Oaks with dark brown leaves, a Beech with 

 golden foliage, and. crimson-fruited Black Alder mingled 

 through it all. This may be readily brought about, for 1 saw 

 it yesterday, where Nature had, without man's .aid or inter- 

 ference, made thus beautiful the corner of a long neglected 

 field. Charles C. Ahholt. 



Near Trenton, New Jersey, April 5th, iSS3. 



How the Mangrove Forms Islands. 



AMONG the agencies that have helped to build up the 

 peninsula of Florida may be numbered certain trees 

 which are fitted by nature to grow on lands that are more 

 or less under water and that are too unsubstantial to sup- 

 port other forms of vegetation. Like the coral builders, 

 they work so slowly that in a single century no great 

 change is accomplished, but in thousands of centuries the 

 changes wrought are very great. The most important of 

 these tree-workers are the Mangrove and the Cypress. The 

 former grows on shores and shoals that are overflowed 

 generally by salt tide-water; the latter in localities that are 

 overflowed at times by fresh water. Both have similar 

 ol>stacles to overcome and they accomplish by this very 

 different means. 



The Red Mangrove {Rhizophora Mangle) covers hun- 

 dreds of square miles of the sovithern shores of Florida, the 

 principal areas occupied by it being the shoals lying be- 

 tween the keys and the mainland — which are composed of 

 calcareous sediment — and the low southern and western 

 borders of the Everglades. In these localities and on tide- 

 washed islands as far north as latitude 29°, it forms a 

 dense thicket of vivid green, rising uniformly from high- 

 water-level, unchanged by seasons, unaffected by hurri- 

 canes, insidiously encroaching on the domain of waters 

 and helping build what in future ages will be dry land. 

 Far in the interior, even on the northern border of the State, 

 are found beds of calcareous sedimentary rock which may 

 once have supported just such thickets of Mangrove. 



In places on the mainland shores the Mangrove attains 

 to tree-like dimensions, forming a tall trunk sometimes two 

 feet in diameter. Like the Cypress, the Mangrove is 

 provided with strong buttresses at the base, but these differ 

 from those of the Cypress in being of the style called by 



architects " flying" buttresses. Starting from the trunk a 

 )'ard or two from its base, they descend in graceful curves, 

 sending off branches, from which other branches proceed, 

 all descending in similar curves to the muddy ground, over 

 which the tides spread twice a day. These basal branches 

 serve the double purpose of props and feeders. From the 

 upper branches, aerial roots descend till they reach the 

 water at high tide. Sometimes a tree maybe seen entirely 

 dead except as to one branch, which is kept green by 

 sucking up water through an aerial root perhaps twenty 

 feet long. 



Another special provision for its environment is seen in 

 the seed of the Mangrove. This, before falling from the 

 branch, develops into a miniature trunk from six to twelve 

 inches long. The basal end being the heaviest, it is most 

 likely to strike the muddy surface first and to stick there in 

 an erect position. The rootlets and seed-leaves being 

 ready to push forth, the young plant makes a rapid growth 

 and soon becomes well rooted and propped in its rather 

 insecure position. 



As the Mangrove usually grows, rising scarcely ten feet 

 from the water and spreading laterally, the main stem is 

 of little importance. Innumerable roots descend from and 

 support the leafy branches, repeatedly forking in their de- 

 scent and forming a sort of basket work below high-water- 

 level. Floating objects become lodged in these natural 

 weirs, shell-fish and other marine creatures multiply in them, 

 and the submerged stems give support to sea-weeds and 

 hydroids. In some localities the roots become encased 

 with oyster-shells, and this, probably, is the origin of many 

 of the oyster-bars that obstruct some of the lagoons or 

 so-called rivers of southern Florida. 



The Mangrove thickets in the course of time build up a 

 foundation for other species. Of these none have a pecu- 

 liar habit of growth, except the Black Mangrove (Avicennia 

 niiidd). This tree is remarkable as to foliage, fruit, wood, 

 bark and roots. The surface-roots send upward innumera- 

 ble short feeders, black, lithe and rising about a span above 

 the surface. This function, evidently, is to draw nutriment 

 from the water at high tide, and, like the knees of the Cy- 

 press, they add to the surface accumulations, which, from 

 age to age, add to the elevation of the land. In this re- 

 spect, however, neither of these trees equals the Red Man- 

 grove. 



The wood of the Red Mangrove sinks in water and is not 

 attacked by marine worms. Hence, fallen branches and 

 trunks remain where they fall, while material that floats in 

 with the tide is detained by the network of basal branches. 

 It is altogether probable that the thousands of tree-covered 

 "islands" in the Everglades and Big Cypress were once 

 Mangrove thickets and that the present Mangrove islands 

 will in time be added to the mainland. As soon as the)' 

 are elevated above the overflow of the tides, the Mangroves 

 will give place to species that require only brackish soil, 

 which, in turn, will be replaced by fresh water or inland 

 forms of vegetation. 



Jacksonville, Fla. -4. H. CurilSS. 



Certain Cone-Eatino; Insects. 



-T-I 



'HE cases here mentioned are the only ones known to 

 J[_ us where the cones of Spruce and Pines have been 

 attacked by insects. It is well known that the Spruce bud 

 louse {Adelges ahieticokns) deforms the terminal shoots of 

 the Spruce, producing large swellings, which would be 

 readily mistaken for the cones of the same tree. Another 

 species of bud louse {Adelges abietis Linn.), which appears 

 to be the same as the European insect of that name, we 

 observed several years since (August, iSSi), in considerable 

 numbers, on the Norway Spruces on the grounds of the 

 Peabody Academy of Sciences at Salem. A species of cat- 

 erpillar {Pinipestis renictdella Grote), was observed August 

 24th, in considerable numbers, on a young Spruce ten to 

 twenty feet in height at Merepoint, on Casco Bay, Maine. 

 The cones on the terminal shoot, as well as the lateral 



